The present invention relates to an integrated circuit device and an electronic instrument.
In recent years, a high-speed serial transfer such as low voltage differential signaling (LVDS) has attracted attention as an interface aiming at reducing EMI noise or the like. In such a high-speed serial transfer, data is transferred by causing a transmitter circuit to transmit serialized data using differential signals and causing a receiver circuit to differentially amplify the differential signals (JP-A-2001-222249).
An ordinary portable telephone includes a first instrument section provided with buttons for inputting a telephone number or characters, a second instrument section provided with a liquid crystal display (LCD) or a camera device, and a connection section (e.g. hinge) which connects the first and second instrument sections. The number of interconnects passing through the connection section can be reduced by transferring data between a first circuit board provided in the first instrument section and a second circuit board provided in the second instrument section by high-speed serial transfer using small-amplitude differential signals.
A display driver (LCD driver) is known as an integrated circuit device which drives a display panel such as a liquid crystal panel. In order to realize a high-speed serial transfer between the first and second instrument sections, a high-speed interface circuit which transfers data through a serial bus must be incorporated into the display driver.
On the other hand, since the differential signals of the high-speed interface circuit have a small voltage amplitude of 0.1 to 1.0 V, the high-speed interface circuit tends to be affected by noise occurring in the driver circuit. Moreover, the driver circuit may be adversely affected by noise occurring in the high-speed interface circuit.